A typical blade mounting arrangement for axial compressor blades on a rotor in a gas turbine engine includes dovetail roots on the blades received in a circumferential dovetail groove in the rotor. The dovetail roots are inserted serially into the groove through a small loading slot until the groove is full. All the blades in the groove are then shifted as a unit until the loading slot is between two blade roots and the blade stage is locked against further movement. A typical locking system for the blades includes an insert in the dovetail groove between the roots of adjacent blades which is jacked into a locking position in a notch in the converging sides of the dovetail groove wall. The insert is jacked into position by a screw which is accessible from between adjacent blades and which bears against the bottom of the dovetail groove. The notch prevents movement of the blade stage but also reduces the durability of the rotor. A blade locking system according to this invention features an insert in the dovetail groove which operates without a corresponding notch in the converging sides of the dovetail groove.